Vehicle-carried inductive pickup device

ABSTRACT

This invention relates to a vehicle-carried inductive pick-up device for inductively picking up signals from the rails of a railway track. The vehicle-carried pick-up device comprises a multi-turn pick-up coil positioned intermediate the ends of an elongated magnetic core, an electrical conductor having a pair of leads connected to the respective ends of the pick-up coil, an insulative potting material for rigidly encapsulating the pick-up coil, core, conductor, and an exterior housing for providing protection from adverse environmental conditions.

United States Patent [191 [451 Apr. 30, 1974 Campbell et al,

[54] VEHICLE-CARRIED INDUCTIVE PICKUP DEVICE [75] Inventors: Richard D. Campbell, I-Iarmarville;

Reed H. Grundy, Murrysville; Peter M. Noble, Valencia; John Q. G. Darrow, Murrysville; Frank H. Pohle, Eighty-Four; Raymond C. Franke, Allison Park, all of Pa.

[73] Assignee: Westinghouse Air Brake Company,

Swissvale, Pa.

22 Filed: Sept. 15, 1969 211 App]. No.2 857,939

[52] US. Cl 246/8, 343/788, 343/873 [51] Int. Cl. H01q 7/08 [58] Field of Search 343/788, 873, 787, 866; 264/272; 336/96; 246/8 [56] References Cited UNITED STATES PATENTS 2,651,713 9/1953 Florencourt 246/8 UX 2,953,785 9/1960 Granqvist....' 343/788 2,968,807 l/l96l Troost et al. 343/787 3,423,757 1/1969 Gilbert 343/788 2,785,399 3/1957 Harris 343/873 X 3,524,982 8/1970 Peterson....; 246/182 B FOREIGN PATENTS OR APPLICATIONS 748,001 4/1956 Great Britain 343/788 OTHER PUBLICATIONS Article by Charles A. Harper in Machine Design, June 9, 1966, p. 150.

Primary Examinp-Gerald M. Forlenza Assistant Examiner-George H. Libman Attorney, Agent, 0rv Firm-J. B. Sotak; H. A. Williamson [5 7] ABSTRACT This invention relates to a vehicle-carried inductive pick-up device for inductively picking up signals from the rails of a railway track. The vehicle-carried pickup device comprises a multi-tum pick-up coil positioned intermediate the ends of an elongated magnetic core, an electrical conductor having a pair of leads connected to the respective ends of the pick-up coil, an insulative potting material for rigidly encapsulating the pick-up coil, core, conductor, and an exterior housing for providing protection from adverse environmental conditions.

9 Claims, 2 Drawing Figures l VEHICLE-CARRIED INDUCTIVE PICKUP DEVICE My invention relates to a vehicle-carried inductive pick-up device.

More specifically, my invention relates to a vehiclecarried inductive pick-up device for inductively picking up signals from the rails of a railway track. The vehiclecarried inductive pick-up device comprises an elongated magnetic core, a multi-turn pick-up coil, an electrical conductor, and an insulative potting material. The multi-turn pick-up coil is positioned intermediate the ends of the elongated magnetic core. The electrical conductor includes a pair of leads which are connected to the respective ends of thepick-up coil. The core, coil, and conductor are all rigidly encapsulated by the potting material and an insulative housing for protecting the coil, core, and conductor from adverse environmental conditions.

In the past, railway cab signaling and automatic train control systems incorporated a vehicle-carried inductive receiving component which included pick-up devices carried on a large cross bar arrangement constructed of laminated magnetic steel. The inductive receiving component was normally mounted on the first vehicle under-carriage in advance of the front wheels. These previous types of inductive receiving components were characterized by extremely large sizes which were not only generally bulky but also relatively heavy, weighing on the order of 250 pounds including mounting hardware. While size and weight did not ordinarily hamper prior art vehicle operation, particularly in conventional train and locomotive cab signal systems, the advent of high speed mass transit type of vehicl es necessitates the need for lightness. Thus, the present day requirements dictate that, if possible, every piece of vehicle-carried apparatus including the inductive receiving component should be small in size and light in weight. A further problem which must be contended with in the prior art cab signaling and automatic train control vehicle-carried receiving components was the ever present danger and possibility of vehicle derailment. That is, in cases where the massive receiving component becomes dislodged from the vehicle underframe, every effort must be taken to ensure that the component does not fall below and under a vehicle wheel. In order to reduce and substantially eliminate vehicle derailment without the need for additional safety support apparatus.

It is therefore an object of our invention to provide a novel vehicle-carried inductive pick-up device which is small in size, light in weight, economic in cost, simple in construction, reliable in operation, durable in use and eficient in service.

Another object of this invention is to provide an improved vehicle-carried inductive pick-up device which eliminates the possibility of vehicle derailment because of its inherent destructibility.

Yet another object of this'invention is to provide a new and improved vehicle-carried inductive pick-up device which is relatively easy to install as well as to maintain.

Still another object of this invention is to provide a novel vehicle-carried inductive pick-up device which eliminates the need for additional supporting apparatus because of its inherent destructibility.

' Still yet another object of this invention is to provide an improved vehicle-carried inductive pick-up device which provides effective dampening against vibration and shock.

A further object of this invention is to provide a unique vehicle-carried inductive pick-up device which has great versatility and adaptability to various vehicle designs and has electrical and magnetic characteristics which allow usage on in-service vehicles and in existing systems.

Yet a further object of this invention is to provide a novel vehicle-carried inductive pick-up device which has a core material which is homogeneous and dimensions held to closer tolerance thereby allowing specific inductance measurement with relative ease.

Still a further object of this invention is to provide an improvedvehicle-carried inductive pick-up device conducive to operation over wide variations in frequency.

In the attainment of the foregoing objects, we provide a vehicle-carried inductive pick-up device which is employed for inductively picking up cab signals from the rails of a railway track. The vehicle-carried inductive pick-up device comprises an elongated ferrite core, a multi-turn pick-up coil, an electrical conductor, a urethene insulative potting material and a fiber glass housing. The multi-turn pick-up coil is positioned interthis type of possible danger, the prior art inductive rev ceiving component, therefore, also required a secondary fastening means usually in the form of suspension chains, which also ultimately increased the overall weight of the vehicle. Thus, while the chains are a necessary requirement from the standpoint of safety, their addition is obviously an undesirable feature with respect to the weight factor, particularly in mass transit operations. In addition, it will be appreciated that an inductive receiving component for a cab signaling system must operate efficiently and reliably in an extremely severe environmental surrounding. For example, in a railroad and mass transit milieu, the inductive pick-up device is constantly exposed to all types of adverse climatic conditions as well as to a highly contaminated environment.

To alleviate the above-mentioned problems, we have developed a new and improved type of vehicle-carried receiving coil which will not detract from the vehicle speed capabilities but will eliminate the possibility of mediate the ends of the elongated ferrite core and is concentrially wound on an annular bobbin through which passes the elongated ferrite core. The electrical conductor has a pair of leads connected to the respective ends of the multi-turn coil. The urethene insulative potting material rigidly encapsulates the core, coil, bobbin, and conductor and the fiber glass housing for protecting the core, coil, bobbin, and conductor from adverse environmental conditions.

Other objects and advantages of our invention will become apparent from the ensuing description of illustrative embodiments thereof, in the course of which reference is had to the accompanying drawings in which:

FIG. 1 illustrates a partial sectional or cutaway longitudinal view of the inductive pick-up device embodying the teachings of the present invention.

FIG. 2 depicts in a diagrammatic form the vehiclecarried inductive pick-up device of FIG. 1 which is carried by a railway vehicle moving along the rails of the railway track.

Reference is now made to the drawings and particularly to FIG. l which illustrates a partial cutaway form of an inductive pick-up device 1 employing the unique concept of the present invention; As shown, an elongated sintered magnetic core 10, which is preferably but not necessarily composed of ferrite material, passes through the circular aperture'of an annular bobbin or spool 11. As shown, a multi-tum pick-up coil 12 is wound upon the central portion of the bobbin 1 1. Bobbin 11 and coil 12 are disposed intermediate the ends of the elongated ferrite core 10. A layer of insulative material, such as vinyl electrical tape 13 is twisted about the central portion of the core to provide a snug fit for the bobbin 11. Secured to one end of the elongated ferrite core 10 is an electrical conductor 15, such as-shielded cable. The cable 15 is conveniently taped to the ferrite core 10 by means of wrappings 18 and 19. As shown, electrical conductor 15 includes a pair of insulated wires 16 and 17 which are connected to the respective ends of the multi-tum pick-up coil 12. The elongated ferrite core 10, multi-turn pick-up coil 12, annular bobbin l1 and electrical conduit 15 are all rigidly encapsulated within insulative material 20 which is preferably composed of an epoxy compound, such as urethane. Thus, these internal elements are protected against adverse effects of dust, dirt, moisture, oil, as well as other foreign matter which is common to a railroad environment. The urethane material also reduces the amount of shock and vibration which is transmitted to the pick-up device due to vehicle movement and gravitational force. lt has been found that further protection may be afforded to the pick-up device by providing an exterior cover or housing 14 Preferably the cover 14 is composed of plastic, such as fiber glass, for inductive reasons. lnpractice, the housing 14 has a square cross-section and includes a suitable opening 21 located in one end through which the conductor 15 p'asseslt has also been found that the housing 14 provides a convenient mold or container for holding the epoxy material during the molding process. It will be understood that the insulative housing 14 could have a circular cross-section or any other geometrical-shaped cross-section so long as insulative and inductive qualities are not impaired. It will further be understood that the insulative housing 14 is not necessarily an essential part of the pick-up device, and hence, the insulative material 20 could also take any geometrical shape so long as insulation and rigid structure is maintained. That is, the internal elements may be placed within a suitably shaped mold and the epoxy material may be poured into the mold and then cured, and thereafter removed therefrom as a coverless pick-up device.

Accordingly, whenever the pick-up device enters a magnetic field a current is induced in the multi-tum coil ll'so that a signal will appear on the leads l6 and 17 of electrical conductor 15. In a cab signaling system,

. the frequency or the modulation thereof of the induced that the railway vehicle 30 is traveling along the rails 34 and 36 in a direction indicated by the arrow 31. The vehicle includes apair. of wheels 32 and 33 which, in this' case, are the leading or front wheels. The rails 34 and 36 may have various speed command signals impressed into them dependent upon the particular section of track that the vehicle is traversing along its route. Since the wheels 32- and 33 of the railway vehicle 30 are mechanically coupled to the axle 37, the coded cab signals flowing through the rails are shunted by the vehicle. Thus, the pick-up device must be mounted forward of the front wheels in order to pick-up the speed command signals from the rails before shunting takes place. To accomplish this, a nonrotatable annular supporting shell 41 is positioned to the left of .thecenter of axle 37 as viewed by an observer of an oncoming vehicle. Since the vehicle for mass or rapid transit operation is provided with roller bearings, the axle 37 rotates while'the supporting shell '41 is relatively fixed with respect to the rotational movement of the wheels. The vehicle-carried inductive pick-up device 1 is suitably secured to the annular support 41 by a substantially L-shaped bracket44 constructed of steel or the like. As shown, one leg or end of bracket 44 is suitably secured by bolts or other fastening means to the annular supporting shell 41. The other leg or end of the bracket 44 extends forward of the wheel and is provided with a suitable clamping type fastener which engages the exterior of the pick-up device l. Thus, the bracket 44 rigidly holds the pick-up device 1 in front of the wheel 32 and slightly above the top of the rail 34. g

lt willbe appreciated that since the vehicle-carried pick-up device 42 is supported on an unsprung portion of the vehicle 3 0,.namely, the supporting shell 41, the vehicle-carried pick-up device 42 is susceptible to maximum vibrating effects. However, as previously mentioned, shock and vibration is reduced and dampened by the encapsulating material 20. Thefastening of the pick-up device to the supporting shell 41 also permits the pick-up device to be mounted closer to the rail without the need of extremely long and heavy supporting brackets. Thus, as the vehicle moves along the track, speed signals are induced into the pick-up device 1. It will be appreciated that different speed signals may ormay not be induced into the device 1 as the vehicle moves from section to section along its route of travel. The electrical conduit 15 is electrically coupled to vehicle-carried decoding equipment 46 which includes suitable'components and circuits for controlling operation of the vehicle 30. In a cab signaling system, the induced signals may be decoded and employed to provide the authorized speed indication for-the operator, and in an automatic train control system the induced signals may be decoded and employed for automatically operating the vehicle'30.

It will be appreciated that the vehicle-carried pick-up and substantially eliminated since the pick-up devicewill be destroyed and crushed by the weight of the vehicle if it should fall under the wheels of vehicle 30. Further, it will be noted that while only one vehicle-carried inductive pick-up devicehas been shown positioned along a vehicle axle 37 near wheel 32, it will be appreciated that a second pick-up device may be similarly positioned at or near wheel 33 and the two devices electrically interconnected to provide increased signal strength. It will also be noted that while the pick-up device is illustrated as having square cross-section, it will be understood that other geometric shapes or configurations may be employed without departing from the spirit and scope of our invention. Further, it will be appreciated that the exterior housing 14 may or may not be employed in practicing our invention.

Thus, it is apparent that the new and improved vehicle-carried inductive pick-up device of the present invention provides a lighter, safer, more compact, less expensive arrangement of picking up signals from the rails of a railway track. Having thus described our invention what we claim is:

l. A vehicle-carried inductive pickup device for inductively picking up signals from a railway track comprising, an elongated magnetic core, a multi-turn pickup coil positioned intermediate the ends of said elongated magnetic core and concentrically wound on an apertured annular bobbin through which said elongated magnetic core passes, an electrical conductor having a pair of leads connected to the respective ends of said coil, and an insulative potting material encapsulating said core, coil and conductor for rigidly holding said core, coil, bobbin and conductor and protecting said coil, core, bobbin and conductor against adverse environmental conditions wherein a layer of insulation is wrapped around the intermediate portion of said elongated magnetic core so that said annular bobbin is snugly fitted on said elongated magnetic core.

2. A vehicle-carried inductive pick-up device as defined in claim 1, wherein the projected axis of said elongated core is substantially perpendicular to longi- 'tudinal axis of the said railway track.

3. A vehicle-carried inductive pick-up device as defined in claim 1, wherein said elongated magnetic core is a ferrite rod.

4. A vehicle-carried inductive pick-up device as defined in claim 1, wherein said insulating material is urethane in which said elongated magnet-core, said coil, said annular bobbin and said conductor are encapsulated.

5. A vehicle-carried inductive pick-up device as defined in claim 1 wherein an exterior housing surrounds said insulative potting material.

6. A vehicle-carried inductive pick-up device as defined in claim 5, wherein said exterior housing is constructed of insulating material.

7. A vehicle-carried inductive pick-up device as defined in claim 5, wherein said insulating material is fiber glass.

8. A vehicle-carried inductive pickup device as defined in claim 1, wherein said device is secured to one end of a bracket which projects forward of the front axle of the vehicle and the other end of which is connected to an axle supporting shell carried by the vehicle.

9. An inductive pickup device comprising, an elongated ferrite core, a multi-turn pickup coil positioned intermediate the ends of said elongated ferrite core and concentrically wound on an annular bobbin through which passes said elongated ferrite core, a layer of insulating material surrounding the elongated ferrite core for providing a snug fit for said annular bobbin, an electrical conductor having a pair of leads connected to the respective ends of said coil, and a urethene insulative material encapsulating said elongated ferrite core, multi-turn coil annular bobbin and conductor, and an external cover member surrounding said urethene insulation material. 

1. A vehicle-carried inductive pickup device for inductively picking up signals from a railway track comprising, an elongated magnetic core, a multi-turn pickup coil positioned intermediate the ends of said elongated magnetic core and concentrically wound on an apertured annular bobbin through which said elongated magnetic core passes, an electrical conductor having a pair of leads connected to the respective ends of said coil, and an insulative potting material encapsulating said core, coil and conductor for rigidly holding said core, coil, bobbin and conductor and protecting said coil, core, bobbin and conductor against adverse environmental conditions wherein a layer of insulation is wrapped around the intermediate portion of said elongated magnetic core so that said annular bobbin is snugly fitted on said elongated magnetic core.
 2. A vehicle-carried inductive pick-up device as defined in claim 1, wherein the projected axis of said elongated core is substantially perpendicular to longitudinal axis of the said railway track.
 3. A vehicle-carried inductive pick-up device as defined in claim 1, wherein said elongated magnetic core is a ferrite rod.
 4. A vehicle-carried inductive pick-up device as defined in claim 1, wherein said insulating material is urethane in which said elongated magnet core, said coil, said annular bobbin and said conductor are encapsulated.
 5. A vehicle-carried inductive pick-up device as defined in claim 1 wherein an exterior housing surrounds said insulative potting material.
 6. A vehicle-carried inductive pick-up device as defined in claim 5, wherein said exterior housing is constructed of insulating material.
 7. A vehicle-carried inductive pick-up device as defined in claim 5, wherein said insulating material is fiber glass.
 8. A vehicle-carried inductive pickup device as defined in claim 1, wherein said device is secured to one end of a bracket which projects forward of the front axle of the vehicle and the other end of which is connected to an axle supporting shell carried by the vehicle.
 9. An inductive pickup device comprising, an elongated ferrite core, a multi-turn pickup coil positioned intermediate the ends of said elongated ferrite core and concentrically wound on an annular bobbin through which passes said elongated ferrite core, a layer of insulating material surrounding the elongated ferrite core for providing a snug fit for said annular bobbin, an electrical conductor having a pair of leads connected to the respective ends of said coil, and a urethene insulative material encapsulating said elongated ferrite core, multi-turn coil annular bobbin and conductor, and an external cover member surrounding said urethene insulation material. 